CONFIG_CPU_HAS_LLSC is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_CPU_HAS_LLSC.
Result is shown for kernelversion 5.4.123

ll/sc Instructions available

configname: CONFIG_CPU_HAS_LLSC

Linux/MIPS Kernel Configuration
└─>CPU selection
└─>ll/sc Instructions available
In linux kernel since version 2.6.12  
MIPS R4000 series and later provide the Load Linked (ll)
and Store Conditional (sc) instructions. More information is
available at <http://www.go-ecs.com/mips/miptek1.htm>.

Say Y here if your CPU has the ll and sc instructions. Say Y here
for better performance, N if you don't know. You must say Y here
for multiprocessor machines.